On another thread I commented that some guns in question might be movie prop guns. Over the years I've seen numerous guns made up in disguise for the movies.

I remember seeing several Colt New Service and S&W Hand Ejector revolvers, fitted with plastic fake stag grips and having rod ejector assemblies added to look like single action Colts. Also saw a Colt Army Special so fitted.

Also several Colt Single Actions that had their ejector assemblies removed and a built up web added under the barrel to simulate a Remington cap-and-ball revolver.

Fitting a Colt 1877 DA (Lightning or Thunderer) with new grip straps to look like a Single Action. This was done, I was told, because the actor could not handle a SA to be fanned. He fired DA but simulated fanning.

And Winchester M92 to represent Henrys by brass plating the receiver and removing the forearm. Close ups clearly show the loading port, however.

Also have seen actors loading a muzzle loader that is actually a Springfield M1873.